Power line communication (PLC) devices can be used in buildings, such as a residential home (e.g., house, condominium, apartment, etc.), to enable data communications across a power system infrastructure, such as power lines of a branch circuit(s). PLC devices conduct communications in the high frequency ranges, such as for example in the unregulated range from 2 MHz to 30 MHz and to as high as 86 MHz (see, e.g., HomePlug Avx and HomePlug GreenPhy). Power line communication protocol used by PLC devices can include, for example, IEEE 1901, IEEE P1901.2, HomePlug GP/AV/AV2/1.0, G.hn, or G.hnem. When PLC devices are employed in a building or other structure along with an arc fault circuit interrupter (AFCI) device, the presence of PLC signals, particularly the high frequency content of their carrier signals may be inadvertently interpreted by the AFCI device as arc fault signals, and thus, may result in nuisance trips by the AFCI device. Accordingly, PLC signals and other high frequency noises may interfere with arc fault detection at the high frequency ranges, e.g., frequency ranges greater than or equal to 1 MHz.
One method to detect the presence of power line carriers is based on the Receiver Signal Strength Indicator (RSSI) of high frequency content of power line carriers. However, the RSSI method does not appear to be robust due to the fact that RSSI does not contain frequency information, and therefore, any arc fault signal could look like a PLC signal or vice-a-versa from the signal strength point of view. This RSSI method thus can not be used to detect for an AF signal.
Another detection method involves selecting a frequency region (e.g., region, band, etc.) that corresponds to one of the notch bands of the power line carriers. The notch bands represent narrow frequency regions that are not enabled or used by the PLC device to conduct communication. However, such a detection method allows only a small window, e.g., a narrow frequency region, for the arcing signals to be detected. Furthermore, such a frequency region might be used by radio stations (e.g., amateur radio) or correspond to a network impedance (resonance/anti-resonance) point which could cause substantial sensitivity issues.